Biological compounds may be used to determine information relating to a subject. For example, the presence of environmental toxins may be determined using biological compounds. Biological compounds may also be used to detect the presence of a disease. For example, the presence of antibodies may indicate that a disease has been detected by a subject's immune system.
Some biological compounds may be found in the skin and/or other areas of the body. Detection and measurement of biological compounds may require expensive equipment, long periods of time and/or other challenges. For example, detection of biological substances in the skin may require removing a sample and performing testing on the sample. Removing samples may cause a subject pain while testing may require that the sample be sent to a lab.
Lipofuscin is a compound found within the human retina. Lipofuscin compounds are generally yellowish pigments typically thought to arise from the progressive oxidation and/or glycation of proteins. In the healthy human body, lipofuscin is relatively uniformly distributed over the retina within the retinal epithelial layer (“RPE”). The formation of lipofuscin is generally thought to be associated with the role of the epithelial layer cells in phagocytosing the outer segment disc membranes that are typically shed daily by the photoreceptor cells. The loss of the outer segment membranes is irreversible since the human body does not replace the photoreceptor cells. Lipofuscin concentrations generally appear to be somewhat higher in the macular region of the retina than in the periphery.
Accordingly, lipofuscin may be used as a biological marker for aging of the human retina and, more generally, the human body. Therefore, benefits may be realized by providing systems and methods for detecting lipofuscin concentration levels in the human retina.